Gasoline particulate filter on-board diagnostic techniques using oxygen sensor heater

Abstract

A diagnostic system and method for a gasoline particulate filter (GPF) of an exhaust system of a vehicle comprise at least one heater associated with at least one oxygen (O2) sensor disposed proximate to the GPF in the exhaust system and a controller configured to determine a status of the GPF based on a duty cycle of the at least one O2 sensor heater and, based on the determined status of the GPF, detect a malfunction of the GPF or whether to regenerate the GPF.

What is claimed is: 
     
         1 . A diagnostic system for a gasoline particulate filter (GPF) of an exhaust system of a vehicle, the system comprising:
 at least one heater associated with at least one oxygen (O2) sensor disposed proximate to the GPF in the exhaust system; and   a controller configured to:
 determine a status of the GPF based on a duty cycle of the at least one O2 sensor heater; and 
 based on the determined status of the GPF, detect a malfunction of the GPF or whether to regenerate the GPF. 
   
     
     
         2 . The system of  claim 1 , wherein
 the at least one heater comprises (i) an upstream heater associated with an upstream O2 sensor disposed upstream from a catalyst of the GPF in the exhaust system and (ii) a downstream heater associated with a downstream O2 sensor disposed downstream from the catalyst of the GPF in the exhaust system; and   the controller is configured to (i) determine the status of the GPF based on duty cycles of the upstream and downstream O2 sensor heaters and (ii) based on the determined GPF status, detect the malfunction of the GPF or whether to regenerate the GPF.   
     
     
         3 . The system of  claim 2 , wherein the controller is configured to determine the status of the GPF based on comparison between (a) a ratio of (i) the duty cycle of the upstream heater to (ii) the duty cycle of the downstream heater and (b) a plurality of predetermined ranges of duty cycle ratios corresponding to different load levels and malfunctions of the GPF. 
     
     
         4 . The system of  claim 2 , wherein the controller is configured to determine the status of the GPF during an engine cold start where the upstream and downstream heaters are active. 
     
     
         5 . The system of  claim 1 , wherein the determined GPF status is indicative of one of the following operating conditions: (i) normal operation, (ii) time to regenerate the GPF, (ii) an overloaded GPF, (iv) a burnt-through or cracked GPF catalyst, and (v) an empty GPF can. 
     
     
         6 . The system of  claim 5 , wherein the controller initiates a regeneration cycle for the GPF when the determined GPF status is indicative of the time to regenerate the GPF. 
     
     
         7 . The system of  claim 5 , wherein the controller detects the malfunction of the GPF when the determined GPF status is indicative of one of the overloaded GPF, the burnt-through or cracked GPF catalyst, and the empty GPF can. 
     
     
         8 . The system of  claim 7 , wherein the controller is further configured to set a fault or failure on-board diagnostic (OBD) flag in response to detecting the malfunction of the GPF. 
     
     
         9 . A diagnostic method for a gasoline particulate filter (GPF) in an exhaust system of a vehicle, the method comprising:
 controlling, based on a target temperature, at least one heater associated with at least one oxygen (O2) sensor disposed proximate to the GPF in the exhaust system;   determining, by a controller, a status of the GPF based on a duty cycle of the at least one O2 sensor heater; and   based on the determined status of the GPF, detecting, by the controller, a malfunction of the GPF or whether to regenerate the GPF.   
     
     
         10 . The method of  claim 9 , wherein:
 the at least one heater comprises (i) an upstream heater associated with an upstream O2 sensor disposed upstream from a catalyst of the GPF in the exhaust system and (ii) a downstream heater associated with a downstream O2 sensor disposed downstream from the catalyst of the GPF in the exhaust system; and   the controller is configured to (i) determine the status of the GPF based on duty cycles of the upstream and downstream O2 sensor heaters and (ii) based on the determined GPF status, detect the malfunction of the GPF or whether to regenerate the GPF.   
     
     
         11 . The method of  claim 10 , wherein the determining of the status of the GPF is based on comparison between (a) a ratio of (i) the duty cycle of the upstream heater to (ii) the duty cycle of the downstream heater and (b) a plurality of predetermined ranges of duty cycle ratios corresponding to different load levels and malfunctions of the GPF. 
     
     
         12 . The method of  claim 10 , wherein the determining of the status of the GPF is during an engine cold start where the upstream and downstream heaters are active. 
     
     
         13 . The method of  claim 9 , wherein the determined GPF status is indicative of one of the following operating conditions: (i) normal operation, (ii) time to regenerate the GPF, (ii) an overloaded GPF, (iv) a burnt-through or cracked GPF catalyst, and (v) an empty GPF can. 
     
     
         14 . The method of  claim 13 , further comprising initiating, by the controller, a regeneration cycle for the GPF when the determined GPF status is indicative of the time to regenerate the GPF. 
     
     
         15 . The method of  claim 13 , further comprising detecting, by the controller, the malfunction of the GPF when the determined GPF status is indicative of one of the overloaded GPF, the burnt-through or cracked GPF catalyst, and the empty GPF can. 
     
     
         16 . The method of  claim 15 , further comprising setting, by the controller, a fault or failure on-board diagnostic (OBD) flag in response to detecting the malfunction of the GPF.